The San Diego Zoo says it set a record for attendance in 2018, seeing more than 4 million visitors for the first time in its 102-year history.

In addition, combined attendance at the zoo and its sister, the San Diego Zoo Safari Park, reached a record of more than 5.5 million. More than 1.5 million visited the Safari Park, east of Escondido.

The zoo's previous record of 3.9 million was set in 1987. That was the year of “pandamonium” -- the first time the zoo had pandas on display. Since then, annual zoo attendance has been in the 3.5 million to 3.7 million range.

Ticket prices have also gone up: A one-day-admission for adults costs $56 this year, up from $54 last year. Children’s admission for those 3-17, costs $46, up from $44 last year. Annual memberships, which provide unlimited admission to both parks, start at $112 for those living in ZIP codes 91900 to 92899, are the same price as last year.

New exhibits, such as the zoo’s Conrad Prebys Africa Rocks and Walkabout Australia at the Safari Park, appear responsible for the increased attendance, said Dwight Scott, director of the San Diego Zoo.

Africa Rocks cost $68 million, funded through local philanthropists, including the late Conrad Prebys. It features penguins, monkeys, other mammals and wildlife native to Africa. These are placed in simulated climatic zones, including the Ethiopian highlands, West African forest, woodlands, rocky outcropping “islands” and the forests of Madagascar.

Walkabout Australia cost $17.4 million, and encompasses 3.6 acres. Its most notable feature is an area where visitors can observe kangaroos, wallabies and magpie geese, with no barriers between them. Visitors stay on a path, but the animals are free to come up to the visitors.

Without the philanthropic support we received (for the two exhibits), that wouldn’t have been possible at all,” Scott said. So ultimately, the donors deserve credit for the increased attendance.

There’s also more parking at the zoo.

‘We built an employee parking structure, right between the zoo and Balboa Park on Old Globe Way. We have a 642-space parking structure. That has allowed us to get our employees out of the zoo parking lot and so now we can have more guests.”

More change is on the way, Scott said. Ground has been broken on a new Children’s Zoo, which philanthropist Denny Sanford is donating to build.

“The intent of the project is to build a wonderful space for children to play in nature and reconnect with nature,” Scott said.

In the rest of the zoo, children must stay on paths to be safe. But the new Children’s Zoo is intended to allow children to explore the environment and have fun.

“We're doing things like creating a large tree house where kids can climb up into, or through an ADA (Americans with Disabilities Act) accessible bridge and look eye to eye with squirrel monkeys in trees,” Scott said.

Visitors will see a lot of creepy-crawlies and flying-crawlies.

“In our current Children’s Zoo, we have a wonderful bug house,” Scott said. “The bugs were so popular that we were outgrowing it. So we’re going to build a large facility for invertebrates from all over the world.”

The site is about 2 ½ acres, just a bit larger than the existing Children’s Zoo.

In addition, visitors may be responding to the zoo’s messages asking help in its mission to save species,” Douglas G. Myers, president and CEO of San Diego Zoo Global, said in a statement.

“This last year, we increased communications about the need to save species and ran advertising asking people to support our efforts by coming to the Zoo and the Safari Park,” Myers said.

San Diego Zoo Global, the parent of the zoo and Safari Park, contributes to conservation programs in the U.S. and internationally.